Too much power problem! (1 Viewer)

[Tapage]

Again my question will be .. which it's the other side " line " job . ?

 

[lostmarbles]

Again my question will be .. which it's the other side " line " job . ?

Yes. If he got "maximum power" when the "other" hose came off - Then I'm completely lost as to why. Because as far as I know - that hose is just used to provide a "base reference pressure" (for want of a better term) for the "diaphragm actuator" (that moves the rack) to compare the vacuum in the other tube against.

With my engine that tube could be left open to the atmosphere - except then it wouldn't take into account the reduced pressure on the downstream-side of the airfilter. But here I'm not (or shouldn't be) talking about MY engine (non-turbo). Eleblanc's engine has a turbo - so his pressure in that "other" line is significantly higher than atmospheric instead of being lower. So if that "other" hose came off HIS engine - I theorise that he would be losing "boost" out of the open hose. (But it is a small hose so that probably has a minor effect as far as power-loss goes.) And the vacuum produced by the venturi (in the "vacuum" hose) would tend to pull the leather diaphragm a shorter distance (being no longer helped by the boost pressure on the other side of the diaphragm - because the hose feeding the boost pressure there fell off) so ............ hey..... the penny is dropping......................so..............................his diaphragm has less tendency to go towards the "idling-fuel-quantity end of the scale" and greater tendency to go towards the "full-power-fuel-quantity end".

Bloody hell - Once again the theory does correspond with what has happened in practice.

Removing that hose on my non-turboed engine does "next to nothing" but removing it on eleblanc's turboed engine gives "a big power boost" - and the theory tells us why.

Cheers Tapage (Thanks for making me think it through properly.)

Now that I understand which hose it was that came off and what was happening - please ignore what I said when I thought it was the vacuum/venturi hose that came off.

If I had a turboed engine - I'd be out experimenting now to see what actually happens if I was to remove that "reference pressure" hose with my engine idling.

 

[joshoisasleep]

I've had both hoses come off lots of times before I finally found somewhere that sold little hose clamps. You're right one seems to do more or less nothing, but I think I remember it still makes a loud noise and things heat up pretty quick anyway.

Yeah maybe you're right that shutting down would have been a better idea... I was also worried that maybe I would crack the block or something if I turned the engine off suddenly at high temps and high revs. In any case I did it my way several times... if you're quick it's not revving high for more than a few seconds.

 

[eleblanc]

Mine didn't scream of the rev. It idle perfectly, just that when i touch the throttle it would go full throttle even a 1/16 movement in the pedal. I drove power on off for about 1 miles before i took a exit. But when it was on, it was pulling ALOT

 

[joshoisasleep]

hmmm that sounds right. It all happened so fast, but if mine did the same which is likely then that could be why I felt comfortable letting it idle for a sec while reattaching the hose

 

[cody c]

Tapage, one side is at the intake manifold near the butterfly valve, the other side is at the injection pump.

 

[Tapage]

I was seen my TB this weekend .. just to figure where get vacc to my BOV .. I would install this next sat .. I just wonder that I would run a T in the vacc line and fit in my signal for BOV :.